1. Department of Oral and Maxillofacial Surgery, Universidad de La Frontera, Temuco, Chile.
2. Center for Research in Biomedical Sciences, Universidad Autónoma de Chile, Temuco, Chile.
3. Department of Oral and Maxillofacial Surgery, Louisiana State University, Shreveport, LA, USA.
4. Deparment of Oral Diagnosis, State University of Campinas, Piracicaba, Brazil.